Device for operating machine cylinders



p 5, 1967 x E. SOMMERER 3,339,461

DEVICE FOR OPERATING MACHINE CYLINDERS Filed May 13, 1965 3 Sheets-Sheet 1 K Imam 35 I \T I l Illiil I INVENTOR E. SQmmerer ATTORNEYS E- SOMMERER DEVICE FOR OPERATING MACHINE CYLINDERS Sept. 5, 1967 Filed May 13, 1965 3 Sheets-Sheet 2 Fig.4

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' DEVICE FOR OPERATING MACHINE CYLINDERS Filed May 15, 1965 5 Sheets-Sheet s ,42 46 [1 Fig.7 34 a- 2 I, T

37 r 45 12 21 25 v 34 ID I 36 21 4'2 46 Flg;9 v Flg.l0 42' INVENTOR E. ommerer ATTORNEYS United States Patent 4 Claims. (61. 91446) ABSTRACT OF THE DISCLOSURE A piston of a working cylinder is operated by a pressure medium from a single separate block having two conduit lines with each line being provided with a check valve, an operating member in front of the check valve for the entry of the pressure medium and a de-aerating operating member in an outlet conduit branching off behind the check valve from the connecting conduit. A single manual lever carried by the block is connected with a cam disc actuating these operating members. The lever can be moved from a closed intermediate position to two operative positions in which the pressure medium is supplied either upwardly or downwardly to the piston.

This invention relates to a device for operating working cylinders with pressure medium supplied through check valves.

It is known in prior art to operate working cylinders of pneumatic or hydraulic devices from one side or alternately from both sides by a pressure medium through check valves and to de-aerate them by separate manually operated conduits.

The provision of check valves, de-aerating valves and corresponding conduits results in a construction of a working cylinder which is quite complicated and which occupies a great deal of space, although such space in many instances, for example, in the case of chucks of machine tools, is hardly available.

An object of the present invention is to eliminate drawbacks of prior art constructions.

Other objects will become apparent in the course of the following specification.

In the accomplishment of the objectives of the present invention it was found advisable to provide an operating device the characteristic feature of which consists in that two check valves, operating devices for two pressure conduits and two de-aerating conduits, as well as conduits interconnecting them, are combined in one independent block with a switching member common to all operating devices, which can be spaced from the working cylinder and is connected therewith by at most two conduits which can serve at will or alternately as pressure conduits or de-aerating conduits.

In accordance with the operating device of the present invention the working cylinder is provided with a bore hole for the connecting conduit either on one side or both sides thereof depending on the operation, with the result that its size is reduced and its construction is simplified to the greatest extent.

The parts of the operating device are arranged in two conduit lines between the source of pressure and separate connecting conduits, whereby each conduit line is provided with a check valve, an operating member in front of the check valve for the entry of the pressure medium and a de-aerating operating member in an outlet conduit branching oif behind the check valve from the connecting conduit.

The operating members are valves which close under 3,339,451 Patented Sept. 5, 1967 spring pressure in the direction of the pressure and which are automatically raised from their seat through lifting members by a switching member consisting of a cam disc with a front cam, preferably provided with a hand lever.

The cam arrangement of the switching member is such that in two positions of the switching members which are spaced by the valve operating the pressure medium of one conduit line and the de-aerating valve of the other conduit line are opened, while all the operating valves are closed in an intermediate position.

The operating device of the present invention is suitable for working cylinders of any desired type with one-sided piston actuation, and is just as suitable for double-operating pistons. In each case the intermediate position of the switching member corresponds to the position of rest of the operating piston in which it can remain in each moment of its movement. In accordance with the present invention in the case of one-sidedly actuated operating piston, only that check valve which corresponds to the pressure-receiving side is connected with the operating cylinder, while the other check valve is closed airtightly to the atmosphere, for example, through a screw cap.

The construction of the operating device of the present invention results in that the pressure conduit and the deaerating conduit have the same cross-sections. Consequently, the piston is under pressure from both sides in each position.

Furthermore, the operating device of the present invention has also the advantage that it can be manufactured particularly easily. This will be more readily apparent from the following detailed description when taken in connection with the accompanying drawings showing, by way of example, a prefer-red embodiment of the inven tive idea.

In the drawings:

FIGURE 1 is a front view of the operating device of the present invention along with the switching member.

FIGURE 2 is a bottom view of the switching member.

FIGURE 3 is a cross section along the line IIIIII of FIG. 2.

FIGURE 3a is a partial cross section along the line IIIa-IIIa of FIG. 2.

FIGURE 4 is a section through the operating device along the line IVIV of FIG. 5.

FIGURE 5 is a view of the operating device which is turned to the right in relation to FIG. 1 to the extent of 90 and with the switching member removed.

FIGURE 6 is a section along the line VI-VI of FIG. 4.

FIGURE 7 illustrates diagrammatically an intermediate position of the switching member.

FIGURE 8 shows the positions of the parts of the operating device corresponding to that of FIG. 7.

FIGURE 9 illustrates diagrammatically a switching of the switching member.

FIGURE 10 shows the positions of the parts of the operating device corresponding to that of FIG. 9.

FIGURE 11 illustrates diagrammatically another switching position of the switching member.

FIGURE 12 shows the positions of the parts of the operating device corresponding to that of FIG. 11.

The operating device of the present invention includes a block having the shape of a four-cornered prism having side surfaces 1, 2, 3 and 4 and front surfaces 5 and 6. Four equal bore holes 7 (FIGS. 1, 4 and 6) are provided upon the side surface 1 in such manner that their axes are located upon the corners of a square the sides of which are parallel to the edges of the side surface 1.

Four equal bore holes 8 (FIGS. 4 and 6) have axes which coincide with the axes of bore holes 7; the bore holes 8 are located upon the opposed side surface 3. Each of the bore holes 8 has an inner annular flange 9 enclosing (3 a narrower space which is connected by a still narrower connecting bore passage 11 with the passage 7 of the side surface 1 which is coaxial therewith.

Each of the bore holes 8 of the side surface 3 receives a separate operating valve 12. All valves 12 are of the same construction. Each valve has a cup-shaped valve plate 13 containing a sealing insert 14 of elastic material, such as Buna or the like, which is fixed therein by a headcarrying screw 15. The shaft 16 of the valve extends outwardly and is slidably guided in a passage formed in a screw-shaped valve covering 17 which tightly closes the bore hole 8 from the outside by means of a sealing ring. A spring 18 presses the valve inwardly against its seat 19 (FIG. 4) which has the shape of a raised annular bead upon the flange 9 leading to the narrower space 10. The height of the bead-shaped seat and of the metallic edge of the valve plate are so dimensioned that when the valve is in the process of closing, first the sealing insert is pressed against the bead-shaped seat and thereafter the insert is compressed and the metal edge of the valve plate engages the flange 9 adjacent the bead.

This valve has the advantage that it provides a reliable tight seat without it being necessary to flange the valve seats.

Threaded plugs 20 are screwed into the bore holes 7 located upon the side surface 1 opposite the operating valves 12. The plugs 20 have inner end surfaces tightly engaging the bottom of the bore holes while their outer end surfaces are located in the same plane as the outer surface of the block. The plugs 20 have a central bore hole in which a pin 21 is slidably located. The pins 21 extend through the connecting bore passages 11 and have inner ends engaging the valve plates 13, namely, the heads of the screws fixing the sealing inserts 14. The outer ends of the pin 21 extend outside of the plugs 20. A sealing sleeve 22 of rubber or the like is located in an inwardly extending recess of each plug and is used to provide an outwardly tight guide for the pin 21.

The switching device is located centrally between the four threaded plugs 20 and is fixed by a screw device 23 having a cam disc 24 and a hand lever 25 (FIG. 1). The cam disc 24 is provided upon its inner front surface with a concentrical groove 26 into which extend the projecting ends of the pins 21. Two projecting cams 27 are situated at diametrically opposed locations of the groove 26 so that when the hand lever 25 is swung into one of the two switching positions which are spaced by 90, two crosswise located pins 21 are pressed rearwardly and the corresponding operating valves are raised from their seats.

The groove 26 has a widened portion 28 located at one side of the cam disc between the two earns 27; three recesses 30, 31 are provided in this widened portion 28 which cooperate with a ball lock 29 upon the side surface 1; each of the two outer recesses 30 corresponds to one of the two above-mentioned switching positions of the switching device resulting in the movement of a pair of pins 21, while the middle recess 31 defines an intermediate position, or a position of rest, in which no pins are actuated, so that all valves are closed.

The cam disc moves over the side surface 1 of the block by means of a rotary bushing 32 located in a recess provided in the surface 1.

Check valves 34 (FIG. 6) are located opposite each other at the front surfaces 5 and 6 of the block in bore holes 33 and are pressed inwardly by springs. The shafts of the valves are guided in a screw-nipple 35 which is used to provide a connection for a conduit leading to the working cylinder.

The check valves 34 as well as the operating valves are preferably constructed as plate valves having a sealing insert upon the front side and a bead-shaped valve seat.

A screw-nipple 36 is provided upon one of the front surfaces, namely, the surface 5 for the attachment of the conduit for the pressure medium.

The side surface 2 is provided with two de-aerating conduits 37.

The described parts are interconnected in a manner shown, for example, in FIG. 8, whereby the connecting joints are shaped as straight bore holes extending perpendicularly to the side surfaces of the block, the outlets of which are tightly closed to the outside by corresponding plugs, such as the plugs 38 in FIG. 4.

A conduit 39 is connected with the screw-nipple 36 for the pressure medium; it leads through branch conduits 40, 40 to the spring-loaded side of operating valves 12. Passages 41, 41' extend behind the operating valves to the sides of check valves 34 which are not subject to spring pressure. The spring-engaged sides of the two check valves are connected through conduits 42, 42 with opposed sides of an operating cylinder 43 provided with a piston 44. Furthermore, outlet passages 45, 45 lead from the spring engaged sides of the check valves to the spring engaged sides of the other two operating valves 12; de-aerating conduits lead from the other sides of the last-mentioned valves. In the case of pneumatic operation these conduits can lead into the open, while in the case of a hydraulic operation they are connected to a supply cylinder.

The following description of the operation of the device of the present invention is applicable to a double acting piston, the four operating valves 12 which are cross-wise actuated by the switching member, being indicated in FIGS. 7-12 by the numerals I, II, III and IV.

FIGURE 7 shows the switching member 24, 25 in the intermediate position in which the central recess 31 is engaged and all pins 21 are located in that portion of the groove 26 which is free of cams (FIG. 2). Then all the check valves and steering valves are closed.

If now for the purpose of raising a load upon the supporting plate 46, the switching member 24, 25 is moved into the position shown in FIG. 9, the cams of the operating disc will raise the operating valves I and IV from their seats. Then the pressure medium flows through the conduit 40, the open valve I and the conduit 41 into the lower check valve and into the channel 45 leading to the operating valve II which, however, is closed. The pressure medium then opens the lower check valve 34 against the action of its spring, and thereupon flows through the conduit 42 into the lower side of the working cylinder 43, pushing the piston 44 upwardly. The other side of the piston is connected by an upper connecting conduit 42 and the open operating valve IV with the upper deaerating conduit 37 As soon as the desired extent of the stroke has been reached, the switching member 24, 25 is moved back to the position of FIG. 7. Since all valves are closed in this position, the supply of further pressure medium ceases, but the pressure medium contained in the working cylinder can not escape.

In order to produce a downwardly directed pressure, for example, in the case of a raising device for the examination of the springs of a vehicle, the switching device 24, 25 is moved into the position shown in FIG. 11, in which the operating valves II and III are open. Then the connections as those shown in FIG. 12, namely, the pressure medium now flows through the upper connection 40', the operating valve III, the conduit 41', the upper check valve 34 and the passages 42' to the upper side of the working cylinder 43, so that the piston 44 is pressed downwardly. The pressure medium which remained on the other side of the piston from the previous operation, can flow through the lower connecting conduit 42 to the lower check valve 34 which is now closed; the pressure medium flows through the conduit 45 and the open operating valve II to the lower de-aerating conduit 37. Sudden movements of the working piston through brake action are thereby prevented.

The switching procedures shown in the drawing take place when as already statedthe operating device of the present invention is used for a double acting piston,

In order to operate a single action piston, for example, a piston which is subjected only to upwardly directed pressure, only the lower check valve 34 is connected with the working cylinder, while the upper check valve is closed to the outside by a cap or the like. For raising purposes the switching member 24, 25 is moved again into the position shown in FIG. 9 and the operating valves I and IV are opened. Then the pressure medium flows through the lower conduit line to the lower side of the operating piston 44 and raises the piston, while the pressure medium is blown out directly into the open from the other side of the operating cylinder 43. For lowering purposes the switching member is again moved to the position shown in FIG. 11, so that the operating valves III and II are opened. However, since there is no connection between the upper check valve and the upper side of the working cylinder, the pressure medium can not reach the upper side of the piston and this side is subjected only to the effect of the load; the pressure medium will be blown out or returned from the lower portion of the working cylinder through the open operating valve II.

It is apparent that the example described above has been given solely by way of illustration and not by way of limitation and that it is subject to many variations, modifications and different applications within the scope of the present invention. All such variations and modifications are to be included within the scope of the present invention.

What is claimed is:

1. In combination with a cylinder and a piston movable in said cylinder, a device for operating said piston, said device comprising a block spaced from said cylinder and having the shape of a four-cornered prism with two front surfaces and two opposed side surfaces, two check valves located in alinement opposite each other upon said front surfaces, f-our passages formed in said block and extending between said two side surfaces, said passages having axes forming four corners of an imaginary square the sides of which extend parallel to the sides of the prism, each of said passages having a wider portion adjacent one side surface and a narrower portion adjacent the other side surface, valves located in the wider portions of said passages and valve-actuating pins located in the narrower portions of said passages, conduits in said block interconnecting said' valves, said block having an opening receiving a pressure medium and communicating with said conduits, other conduits connected with said check valves and with said cylinder on opposite sides of said piston, and a single switching device carried by said block and having cams actuating said pins, the last-mentioned conduits serving as pressure transmitting as well as dc-aeratin-g conduits.

2. A device in accordance with claim 1, wherein the conduits interconnecting said valves consist of straight bore holes formed in the block, at least some of these conduits being air-tightly closed to the outside.

3. A device in accordance with claim 1, comprising a cam disc carrying said cams, wherein said block has a recess formed upon one of the sides thereof and receiving said cam disc, a screw carried by said block, said cam disc being rotatably mounted upon said screw and having three recesses corresponding to the three positions thereof, and a ball lock adapted to engage any one of said three recesses.

4. A device in accordance with claim 3, comprising a hand lever connected with said cam disc.

References Cited UNITED STATES PATENTS 2,420,588 5/1947 Dunnihoo 137627 2,654,560 10/ 1953 Smith 251-332 2,671,433 3/1954 Meddock 91-446 3,191,617 6/1965 Maddox 251332 3,221,609 12/1965 Frantz 91446 3,224,343 12/ 1965 Nevulis 137--596.2

FOREIGN PATENTS 1,336,718 6/ 1962 France.

MARTIN P. SCHWADRON, Primary Examiner. B. L. ADAMS, Assistant Examiner. 

1. IN COMBINATION WITH A CYLINDER AND A PISTON MOVABLE IN SAID CYLINDER, A DEVICE FOR OPERATING SAID PISTON, SAID DEVICE COMPRISING A BLOCK SPACED FROM SAID CYLINDER AND HAVING THE SHAPE OF A FOUR-CORNERED PRISM WITH TWO FRONT SURFACES AND TWO OPPOSED SIDE SURFACES, TWO CHECK VALVES LOCATED IN ALINEMENT OPPOSITE EACH OTHER UPON SAID FRONT SURFACES, FOUR PASSAGES FORMED IN SAID BLOCK AND EXTENDING BETWEEN SAID TWO SIDE SURFACES, SAID PASSAGES HAVING AXES FORMING FOUR CORNERS OF AN IMAGINARY SQUARE THE SIDES OF WHICH EXTEND PARALLEL TO THE SIDES OF THE PRISM, EACH OF SAID PASSAGE HAVING A WIDER PORTION ADJACENT ONE SIDE SURFACE AND A NARROWER PORTION ADJACENT THE OTHER SIDE SURFACE, VALVE LOCATED IN THE WIDER PORTION OF SAID PASSAGES AND VALVE-ACTUATING PINS LOCATED IN THE NARROWER PORTIONS OF SAID PASSAGES, CONDUITS IN SAID BLOCK INTERCONNECTING SAID VALVE, SAID BLOCK HAVING AN OPENING RECEIVING A PRESSURE MEDIUM AND COMMUNICATING WITH SAID CONDUITS, OTHER CONDUITS CONNECTED WITH SAID CHECK VALVES AND WITH SAID CYLINDER ON OPPOSITE SIDES OF SAID PISTON AND A SINGLE SWITCHING DEVICE CARRIED BY SAID BLOCK AND HAVING CAMS ACTUATING SAID PINS, THE LAST-MENTIONED CONDUITS SERVING AS PRESSURE TRANSMITTING AS WELL AS DE-AERATING CONDUITS. 